Top-level police officials across Asia had been in contact for months as they prepared a sweeping crackdown on fraud rings in half a dozen countries. Last week, they finally struck.
Nearly 600 suspects were rounded up as law enforcers launched a coordinated attack on Internet and telephone scams in an operation that many police and experts said marked a milestone in the regional fight against crime.
"It was unprecedented considering how many countries were involved and how many police officers were mobilised," said Liao Yu-lu, chief of the Department of Criminal Investigation at Taiwan's Central Police University.
Arrests were made in Taiwan, Cambodia, Indonesia, Malaysia, Thailand and -- crucially -- China.
China's prominent role was unmistakable. Most victims of the fraud schemes were Chinese, as were many of the perpetrators. And the impetus to deal a devastating blow to regional vice was Chinese too.
Indonesian police transnational security chief Agung Sabar Santoso said that China, along with Taiwan, had taken the initiative to launch the operation against the fraud suspects.
"Chinese and Taiwanese police teams came to Indonesia and several countries to talk about the case and discuss the details before we launched the operation," Santoso told AFP.
"What happened was quite unique as the operation was carried out at the same time, very fast, involving a number of countries, with a very high level of coordination."
This could herald a new age of regional law enforcement, where Chinese officials cooperate more closely with their Southeast Asian counterparts to deal with the transnational menace of organised crime.
In Cambodia, where about 166 people were held last week, national police spokesman Kirt Chantharith lifted the veil on some of the meticulous planning that had gone before the crackdown -- and China's key role in it.
"Chinese police initiated it. They travelled to meet with us about one or two months ago. They gave us the information and asked us to investigate the crime," he told AFP.
The methods adopted by the criminals varied, but one common approach was to rent an apartment with broadband access, using the Internet for phone calls to victims in the region at a rate of hundreds or even thousands a day.
Once the fraudsters had caught the attention of a potential target, they would seek to obtain credit card details by faking a lottery win or saying that a bank account had been suspended.
Although many of the victims -- as well as the perpetrators -- on this occasion were Chinese, the criminals are spreading their tentacles.
"China faced this scam problem first, but in the past two years it has spread to Thailand," said Panya Maman, deputy commander of Royal Thai Police Crime Investigation Bureau.
One reason that Chinese and Taiwanese fraud rings have begun penetrating into Southeast Asia is that more vigorous law enforcement in China has forced them to seek new markets.
This also goes to show that given the big potential gains, no police victory, including last week's sweep, is likely to be more than a temporary win at most.
"We've got to be vigilant. When you chop off one syndicate, another springs up," said Malaysian Federal Commercial Crimes chief Syed Ismail Syed Azizan.
"The cooperation must be ongoing. This is the only way forward to deal with these syndicates to prevent them from becoming bigger."
Like all savvy business people, regional criminals have proved adept at using the newest technologies, including the Internet.
Timur Pradopo, the chief of Indonesia's national police, said that cyber crime is a predictable consequence of the spread of technology, arguing that special capabilities will be needed to tackle the menace.
"To anticipate the cyber crime, we have to improve our investigation methods and we need to equip our investigators with special skills to deal with the technology crime," he told reporters.
Since 2009, cross-border police work in Southeast Asia has been facilitated by an organisation known as "Aseanpol", bringing together security agencies from the ten members of the Association of Southeast Asian Nations.
China is unlikely to become a member, but it will probably seek to exert some measure of influence anyway, said Mon Wei-teh, chief of Taiwan's Central Police University's Department of Foreign Affairs Police.
"Although China is not a member of the Aseanpol, it is unlikely that Beijing would not show interest in the regional organisation... Beijing could become a dominant power in it," he said.